CROSS REFERENCE TO RELATED APPLICATION
[0001] The present application claims priority to United States Non-provisional Application
Serial No.
14/315,749 filed June 26, 2014, the disclosure of which is incorporated herein by reference in its entirety.
FIELD OF THE INVENTION
[0002] The invention relates to devices and methods for the repair of the functioning of
heart valves, in particular the mitral valve.
BACKGROUND OF THE INVENTION
[0003] Heart valves regulate the movement of blood into and out of the chambers of the heart.
The mitral valve, positioned between the left atrium and the left ventricle, can be
subject to a condition known as mitral regurgitation, in which the mitral valve does
not close properly and some backflow of blood occurs from the left ventricle back
into the left atrium. For example, a mitral valve leaflet can experience prolapse
during systole, thereby inhibiting leaflet coaptation and permitting backflow of blood
into the left atrium.
[0004] Various procedures and devices have been proposed to address the condition of mitral
regurgitation. For example, some mitral valve repair procedures involve removing a
section of a valve leaflet in order to reduce its propensity for prolapse. Other procedures
involve mitral valve replacement. The MITRACLIP (Abbott Vascular) is a device intended
to be positioned across the mitral valve to create a double orifice, in an effort
to allow the valve to close fully during systole.
[0005] US 2010/0331971 discloses cardiac valve downsizing devices and methods. The objective of these downsizing
devices is to downsize the annulus of the valve by circumflexing all or substantially
all of the chords. A downsizing device as disclosed in
US 2010/0331971 is formed as a helix wherein a lower part of the helix is designed to extend on the
ventricular side of the valve along an outer periphery adjacent the heart wall around
the outermost chords. This outer periphery is accessed by extending the helix through
a commissure at the periphery of the valve or through the annulus itself. Rotating
the helix causes advancement of the helix so that part of the helix extends into the
ventricle at the outer periphery around the outermost chords, while part of the helix
is in the atrium, adjacent the annulus, thereby anchoring the device with respect
to the atrium.
[0006] The Applicant's prior application
US 2013/0006352 also relates to devices and methods for the repair of the functioning of heart valves.
US 2013/0006352 discloses heart valve repair devices designed to draw the desired leaflet edge areas
together. A device as disclosed in
US 2013/0006352 comprises a first section having a generally spiral shape, with the spiral shape
emanating from a center of the spiral, and a second section connected to the first
section at the center of the first section. The first section is positioned on the
ventricular side of the heart valve, with the selected chords positioned within the
path of the generally spiral shape, and the second section is positioned on the atrial
side of the heart valve.
US 2013/0006352 discloses that, in a device as described therein, the ventricular section draws the
captured chords together, thereby pulling the desired valve leaflet areas together,
while the atrial section stabilizes or anchors the device relative to the atrium.
[0007] There is a continuing need for improved treatment for mitral valve regurgitation
and for the repair of the functioning of heart valves in general. The various procedures
and devices previously proposed can be improved upon in terms of their overall clinical
outcome, ease of use, reduction of procedure time and risk, and/or reduction of cost.
SUMMARY OF THE INVENTION
[0008] The present invention provides devices and methods for the repair of the functioning
of heart valves.
[0009] In prior heart valve repair devices for capturing leaflet chords as exemplified in
certain prior devices as discussed above, the devices have included parts or sections
for anchoring the devices relative to the atrium, in order to ensure that the devices
remained stable in the heart once implanted. The inventive heart valve repair devices
as described herein depart from these prior teachings. A heart valve repair device
as described herein comprises a ventricular winding for capturing leaflet chords and
drawing them together, without having any connected atrial stabilizing section that
stabilizes or anchors the device relative to the atrium. The device, without any atrial
stabilizing section, has freedom to move with respect to the atrium, providing previously
unrecognized advantages as described below that could not be attained by prior devices
that were anchored to the atrium. While prior devices as discussed above have included
atrial anchoring in order to ensure stability after implantation, the inventors have
found, in both
ex vivo testing and
in vivo animal testing, that a device as described herein with a ventricular winding and
without a connected atrial stabilizing section is sufficiently held in place by the
interaction between the ventricular winding and the chords, thereby allowing the device
to be practiced without a connected atrial stabilizing section, realizing advantages
as described herein.
[0010] In some embodiments, the implantable heart valve repair device comprises, consists
essentially of, or consists of a ventricular winding having a generally spiral shape
adapted to be positioned on a ventricular side of the heart valve such that chords
associated with the heart valve are positioned within the path of the generally spiral
shape of the ventricular winding. The ventricular winding is designed to draw chords
associated with the heart valve closer together, thereby pulling the valve leaflets
closer together in order to facilitate their coaptation and proper closing. The implantable
heart valve repair device in these embodiments is "free of any atrial stabilizing
section," meaning that the device does not have any part that is adapted to stabilize
the device by engaging tissue on the atrial side of the valve, such as the wall of
the atrium or the annulus of the valve on the atrial side.
[0011] In some embodiments, the implantable heart valve repair device has a stabilizing
section that consists only of a ventricular stabilizing section that is adapted to
engage tissue only on the ventricular side of the valve. The ventricular stabilizing
section may consist essentially of, or consist only of, or may be in the form of a
ventricular winding having a generally spiral shape as described above for drawing
chords associated with the heart valve together. The ventricular winding is adapted
to engage tissue only on the ventricular side of the valve, and the ventricular winding
stabilizes the device by the interaction between the ventricular winding and the chords
on the ventricular side of the valve.
[0012] In some embodiments, the implantable heart valve repair device may include a grasping
element for facilitating grasping and maneuvering the device during implantation.
In some embodiments, the implantable heart valve repair device may include an end
portion that is bent downwardly from the general plane of the ventricular winding.
In some embodiments, the implantable heart valve repair device may include one or
more anti-rotation elements for resisting a backwards rotation of the ventricular
winding.
[0013] In some embodiments of a method of repairing a heart valve, a heart valve repair
device is delivered to the area of the heart valve, wherein the device comprises,
consists essentially of, or consists of a ventricular winding having a generally spiral
shape. The method further includes positioning the ventricular winding on a ventricular
side of the heart valve such that chords associated with the heart valve are positioned
within the path of the generally spiral shape of the ventricular winding. The step
of positioning the ventricular winding may further include turning the ventricular
winding in a first direction such that the chords move closer to the center of the
ventricular winding. This movement of the chords pulls the valve leaflets closer together
in order to facilitate their coaptation and proper closing. The method may be practiced
with a heart valve repair device that is free of any atrial stabilizing section, as
described above.
[0014] In some embodiments of a delivery system for implanting a heart valve repair device,
the delivery system comprises an applicator tube and an internal rod within the applicator
tube. The internal rod may be adapted to hold the heart valve repair device during
maneuvering of the device. The delivery system is adapted to release the heart valve
repair device after positioning of the heart valve repair device in the desired location.
The delivery system may include a window through which all or part of the heart valve
repair device may be ejected. The delivery system may also include a ramp surface
for facilitating ejection of the heart valve repair device.
BRIEF DESCRIPTION OF THE DRAWINGS
[0015]
FIG. 1 shows a perspective view of an embodiment of a heart valve repair device.
FIG. 2 shows a side view of another embodiment of a heart valve repair device.
FIG. 3 shows a side view of another embodiment of a heart valve repair device.
FIG. 4 shows a top view of another embodiment of a heart valve repair device.
FIGS. 5A-5C show alternative versions of heart valve repair devices with anti-rotation
elements.
FIG. 6 illustrates a proximal end of a delivery system for implanting a heart valve
repair device.
FIG. 7A shows a top view of a distal end of the delivery system of FIG. 6.
FIG. 7B shows a side view of a distal end of the delivery system of FIG. 6.
FIG. 8 shows a perspective view of the distal end of the delivery system of FIG. 6
with a heart valve repair device being held by the delivery system.
FIG. 9 shows a perspective view of the distal end of the delivery system of FIG. 6
with a heart valve repair device being ejected from the delivery system.
FIG. 10 shows a retention wire threaded through a grasping element of a heart valve
repair device.
FIG. 11 shows another embodiment of a delivery system hook and grasping element.
FIG. 12 shows a top view diagram of leaflets of a mitral valve.
DETAILED DESCRIPTION
[0016] The Applicant's prior application
US 2013/0006352 discloses various heart valve repair devices and methods of implanting them. The
disclosure of
US 2013/0006352 is hereby expressly incorporated herein by reference.
[0017] Certain embodiments of heart valve repair devices and methods of using them are described
herein with reference to the accompanying drawings. These embodiments are only examples,
as numerous variations of the invention disclosed herein are possible within the scope
of the appended claims.
[0018] FIG. 1 shows a first embodiment of a heart valve assisting device 110. The device
110 comprises a ventricular winding 112 and a grasping element 120. As described below,
the ventricular winding 112 serves the functions of both facilitating valve leaflet
coaptation and stabilizing or anchoring the device with respect to the chords.
[0019] The term "spiral" is used herein to refer broadly to shapes defined by a structure
forming a winding around a center wherein the winding gradually moves away from the
center as it winds around the center. The structure of the winding may begin or emanate
from an area at or near the center of the winding. The winding may move away from
the center at a constant rate or at a non-constant rate, and the general outline of
the spiral may take various shapes, such as substantially circular, substantially
elliptical, or other shapes. The spiral may be symmetrical or asymmetrical, and the
center around which the winding structure winds may be a point at the geometric center
of the spiral or a point that is offset from the geometric center of the spiral. The
winding may be in one plane, such that the spiral is substantially flat. Alternatively,
the winding may not be in one plane, with the winding moving up or down at a constant
or non-constant rate. Thus, for example, the spiral may be substantially conical.
The winding may make multiple turns around the center or less than a full turn around
the center. The winding structure of the spiral forms a path that starts from an opening
at the outer periphery of the spiral and that moves toward the center of the spiral
as the path winds around the center of the spiral.
[0020] As can be seen in FIG. 1, the ventricular winding 112 has a generally spiral shape.
The spiral shape is defined by the wire structure of the ventricular winding 112 forming
a winding around a center 114 of the ventricular winding 112, wherein the wire structure
of the winding begins or emanates from an area at or near the center 114 and gradually
moves away from the center 114 as it winds around the center 114. In the case of FIG.
1, the winding of the ventricular winding 112 moves away from the center 114 at a
generally constant rate, and the general outline of the spiral of the ventricular
winding 112 has a substantially circular shape.
[0021] In the embodiment of FIG. 1, the ventricular winding 112 is generally in one plane,
with an end portion 124 of the ventricular winding 112 being bent or angled downwardly
as shown. In an alternative embodiment, the ventricular winding 112 may move gradually
out of plane.
[0022] As shown in FIG. 1, the winding structure of the ventricular winding 112 forms a
path 118 that starts from an opening 116 at the outer periphery of the spiral and
that moves toward the center 114 of the spiral as the path 118 winds around the center
114 of the spiral. In this illustrated embodiment, the path 118 comprises about three
turns around the center 114. More or fewer turns may be used.
[0023] As described above, the spiral may take other shapes. In addition, the ventricular
winding may be comprised of more than one spiral. For example, the ventricular winding
may have two, three, four, or more spirals, which may be similar or dissimilar to
each other. In one example, two spirals may emanate from a common center, each being
similar to the other except that each starts in a direction that is 180 degrees from
the other. This example results in nested spirals in which the opening of each of
the spirals is 180 degrees from the opening of the other spiral. In other examples,
three spirals may emanate from a common center, starting 120 degrees apart and having
openings 120 degrees apart, or four spirals may emanate from a common center, starting
90 degrees apart and having openings 90 degrees apart.
[0024] The overall diameter D1 of the ventricular winding may be substantially smaller than
the diameter of the annulus of the valve. This enables maneuvering the ventricular
winding to capture only selected groups of chords, in order to pull together desired
areas of the valve leaflets. For example, the overall diameter D1 of the ventricular
winding 112 may be approximately 1.0-2.0 centimeters (e.g., 1.2, 1.5, or 1.8 centimeters),
but larger or smaller diameters are possible.
[0025] At its outer end, the ventricular winding 112 terminates at the end portion 124.
In the embodiment of FIG. 1, the end portion 124 is bent downwardly from the general
plane of the ventricular winding 112. The end portion 124 is formed as a loop of the
wire structure of the ventricular winding 112, connected at junction 126. In this
manner, the end portion 124 terminates at a rounded atraumatic tip 125.
[0026] In this embodiment, the length of the end portion 124 is approximately 5 mm, and
it may have other lengths, such as 8 mm, or longer or shorter lengths. The end portion
124 in this embodiment bends downwardly from the general plane of the ventricular
winding 112 by an angle of approximately 15 degrees, and it may bend at other angles,
such as 25 degrees, or larger or smaller angles. In this embodiment, the design results
in a gap in the axial direction between the general plane of the ventricular winding
112 and the tip 125 of the end portion 124 of approximately 1 mm to 5 mm, but larger
or smaller gaps are possible.
[0027] The grasping element 120 is connected to the center 114 of the ventricular winding
112 and extends upwardly from the center 114 of the ventricular winding 112. As shown
in FIG. 1, the grasping element 120 is formed of a continuation of the wire structure
of the ventricular winding 112. The wire structure forming the grasping element 120
extends upwardly from the general plane of the ventricular winding 112 at an angle
of approximately 90 degrees, although other angles may be used. After extending upwardly
from the ventricular winding 112, the wire structure of the grasping element 120 bends
at a top bend 121 and extends downwardly to an end 122 of the wire structure, thereby
forming a loop. The top bend 121 forms an atraumatic tip, and the end 122 may be blunt
or rounded or may form a junction with the adjacent portion of the wire structure,
similar to the junction 126. In alternative embodiments, the grasping element 120
may be substantially straight, curved, bent, helical, or any other suitable shape.
In one example, the length of the grasping element 120 (from the connection with the
ventricular winding 112 to its top at bend 121) may be approximately 5 mm to 20 mm,
for example 6 mm to 8 mm or 10 mm, but longer or shorter lengths are possible.
[0028] As can be seen in FIG. 1, the implantable heart valve repair device 110 is free of
any atrial stabilizing section, i.e., the device does not have any part that is adapted
to stabilize the device by engaging tissue on the atrial side of the valve, such as
the wall of the atrium or the annulus of the valve on the atrial side. It is possible,
for example, that after implantation the grasping element 120 extends through the
valve to the atrial side, and it may contact the leaflets as they close. However,
neither the grasping element 120 nor any other part of the device 110 is adapted to
engage tissue on the atrial side of the valve in a manner that stabilizes or anchors
the device with respect to the atrium.
[0029] The device 110, including the ventricular winding 112 and the grasping element 120,
is comprised of a wire. In alternative embodiments, all or part of the device may
comprise a wire, a bundle of wires, a strip, a rod, or a tube, and different sections
of the device or parts thereof may comprise a wire, a bundle of wires, a strip, a
rod, a tube, or a combination thereof. The structure may be formed by bending or otherwise
shaping a wire, a bundle of wires, a strip, a rod, or a tube into the desired shape.
The desired shape may be obtained by "baking" the material in a certain shape at a
certain temperature such that the material will remember that shape. Alternatively,
the shape may be formed as the wire, bundle of wires, strip, rod, or tube is formed.
For example, the spiral shape of the ventricular winding may be chemically or laser
etched or otherwise cut from a sheet of material, in which case the strip or rod is
formed simultaneously with the spiral shape. The device may be formed of more than
a single structure or material; for example, a tube with a wire core may form the
ventricular winding and/or the grasping element, with the other element formed of
a similar or dissimilar structural component.
[0030] The use of a bundle of wires can provide the device with high axial strength as well
as high flexibility. For example, the use of several thin wires in a twisted bundle
or in a braided bundle provides high axial strength and flexibility that can be determined
by the twisting or braiding structure.
[0031] The wire, bundle of wires, strip, rod or tube may have any suitable cross-sectional
shape. For example, the wire, bundle of wires, strip, rod or tube may have a circular,
elliptical, square, rectangular, hexagonal, or other cross-sectional shape. The wire,
bundle of wires, strip, rod, or tube may have different cross-sectional shapes or
sizes at different places along its length. The wire of device 110 has a circular
cross-sectional shape along its length. In one example, the wire, bundle of wires,
strip, rod, or tube may have a diameter, width or thickness of approximately 0.2-1.0
millimeters (e.g., 0.4 millimeters), but larger or smaller dimensions are possible.
[0032] The wire of device 110 is formed from a suitable shape memory metal, for example
nitinol. Other suitable materials may be used for all or part of the wire(s), rod(s),
or tube(s) of the device, for example other shape memory materials, other metallic
materials, plastic materials and/or composite materials.
[0033] The device 110 of FIG. 1 has rounded ends 121, 125 at the ends of the grasping element
120 and end portion 124. In alternative embodiments, one or more ends of the wire,
bundle of wires, strip, rod, or tube may be rounded, squared-off, or pointed. As described
further below, the device may have one or more anti-rotation elements.
[0034] As can be seen in FIG. 1, the spiral of ventricular winding 112 can be considered
as being wound in a clockwise direction when viewed from the top and starting from
the center and moving outward. In an alternative embodiment, the spiral of the ventricular
winding 112 can be wound in an opposite direction.
[0035] The wire, bundle of wires, strip, rod, or tube may have one or more grooves in its
outer surface. The groove in the outer surface of the wire, bundle of wires, strip,
rod, or tube may extend around the perimeter of the wire, bundle of wires, strip,
rod, or tube and/or in the direction of the length of the wire, bundle of wires, strip,
rod, or tube. As one example, the wire, bundle of wires, strip, rod, or tube may have
one more grooves that extend in a substantially helical path along the wire, bundle
of wires, strip, rod, or tube. Such grooves may serve different purposes. For example,
one or more grooves may be used to create different flexibilities at different places
of the device, to facilitate ingrowth of tissue, to facilitate grasping and manipulation
(e.g., pushing, pulling, turning, etc.) of the device, and/or as channels for drug
delivery. For example, a helical groove can be used to facilitate rotation of the
device as it is being delivered from or withdrawn into a delivery catheter. Similarly,
a helical or other groove can direct cell growth in layers in a preferred direction,
thereby reducing scar formation.
[0036] The wire, bundle of wires, strip, rod, or tube may have one or more holes in it.
The holes may be through-holes extending all the way through the thickness of the
wire, bundle of wires, strip, rod, or tube, and/or the holes may be pockets or dimples
in the outer surface of the wire, bundle of wires, strip, rod, or tube. The holes
may be a series of holes extending along the length and around the periphery of the
wire, bundle of wires, strip, rod, or tube. The holes may serve different purposes.
For example, one or more holes may be used to create different flexibilities at different
places of the device, to facilitate ingrowth of tissue, to facilitate grasping and
manipulation of the device, to provide ports for injection of a contrast agent, and/or
as sites for drug delivery.
[0037] The device may comprise a coating on the wire, bundle of wires, strip, rod, or tube.
The coating is preferably a biocompatible coating that may be used, for example, to
reduce possible negative reactions from the tissue where the device is implanted,
to reduce friction (as a lubricious coating) to assist in delivery of the device,
to reduce friction in areas where the device is designed to be moved against tissue
(for example, along the path of the spiral of the ventricular winding), to increase
friction in areas where it is desired to reduce movement or to anchor the device,
to deliver a suitable drug, for radiopacity, to encourage cell and tissue growth that
would assist in fixation (e.g., of the upper section), to encourage tissue growth
between the chords and/or leaflets, and/or for other purposes. With respect to radiopacity,
the entire device or selected points on the device may be coated or plated with a
material allowing the physician to understand the location of the device during and/or
after the implantation procedure. For example, the ends of the spiral may be plated
with a radiopaque material. If selected points on the device are plated, the plating
at the selected points may have a certain shape (e.g., a line, arrow, etc.) to assist
in understanding the orientation of the device. In another example, in the case of
a device formed of a tube, the tube may be coated to ensure that the coated tube is
sealed in order that the tube may be used, for example, for pressure measurement.
When the coating is a drug-release coating, the coating may comprise a carrier (for
example, a polymer) with the drug in the carrier for drug elution over a suitable
period of time. The drug eluting mechanism may use a biodegradable carrier (e.g.,
a biodegradable polymer) or a stable carrier (e.g., a stable polymer) that allows
the drug elution through diffusion of drug molecules.
[0038] FIG. 2 shows another embodiment of a heart valve repair device 130. The device 130
comprises a ventricular winding 132 and a grasping element 140. The ventricular winding
132 has a generally spiral shape, defined by the wire structure of the ventricular
winding 132 forming a winding around a center 134 of the ventricular winding 132.
The wire structure of the winding emanates from the center 134 and gradually moves
away from the center 134 as it winds around the center 134. In the case of device
130, the winding of the ventricular winding 132 moves outward from the center 134
at a generally constant rate, thereby forming a substantially circular shape (in top
view), while at the same time the winding moves upward from its starting point at
the center 134, thereby forming a substantially conical helix opening upward, with
the base of the cone above the vertex. In an alternative embodiment, the winding of
the ventricular winding moves outward from its starting point at the center while
at the same time moving downward from its starting point at the center, thereby forming
a substantially conical helix opening downward, with the base of the cone below the
vertex. As shown in FIG. 2, the ventricular winding 132 terminates at its outer periphery
at an atraumatic end portion 144, which is bent downwardly, similar to end portion
124.
[0039] In the device 130, like the device 110, the winding structure of the ventricular
winding 132 forms a path that starts from an opening at the outer periphery of the
spiral and that moves toward the center 134 of the spiral as the path winds around
the center 134 of the spiral.
[0040] The device 130, like the device 110, may be comprised of a wire having a circular
cross-section. The wire of device 130 may be formed of a suitable shape memory metal,
for example nitinol.
[0041] The grasping element 140 of device 130 is similar in construction to the grasping
element 120 of device 110. As can be seen in FIG. 2, the device 130 is free of any
atrial stabilizing section.
[0042] As would be understood by persons of ordinary skill in the art from the above descriptions,
alternative embodiments of the device 130 may be formed, using the variations described
above with respect to the device 110. Thus, for example, the ventricular winding 132
and the grasping element 140 may comprise other forms, shapes, sizes and/or materials
as described above with respect to the device 110. The ends of the device may be rounded,
squared-off, or pointed. The device 130 may have one or more anti-rotation elements,
as described further below. The ventricular winding 132 and/or the grasping element
140 may have one or more grooves and/or holes, as described above. The device may
comprise a coating, as described above.
[0043] FIG. 3 shows another embodiment of a heart valve repair device 150. The device 150
comprises a ventricular winding 152 and a grasping element 160. The ventricular winding
152 has a generally spiral shape, defined by the wire structure of the ventricular
winding 152 forming a winding around a center 154 of the ventricular winding 152.
The wire structure of the winding emanates from the center 154 and gradually moves
away from the center 154 as it winds around the center 154. In the case of device
150, in an inner section 151, the winding of the ventricular winding 152 moves outward
from the center 154 at a generally constant rate, thereby forming a substantially
circular shape (in top view), while at the same time the winding moves upward from
its starting point at the center 154, thereby forming a substantially conical helix
opening upward, with the base of the cone above the vertex. Then, the inner section
151 transitions to an outer section 153, in which the winding of the ventricular winding
152 stays substantially in a single plane as it moves outward from the center 154
at a generally constant rate. In an alternative embodiment, the inner section may
stay substantially in a single plane with the outer section forming a section of a
substantially conical helix. As shown in FIG. 3, the ventricular winding 152 terminates
at its outer periphery at an atraumatic end portion 164, which is bent downwardly,
similar to end portion 124.
[0044] In the device 150, like the device 110, the winding structure of the ventricular
winding 152 forms a path that starts from an opening at the outer periphery of the
spiral and that moves toward the center 154 of the spiral as the path winds around
the center 154 of the spiral.
[0045] The device 150, like the device 110, may be comprised of a wire having a circular
cross-section. The wire of device 150 may be formed of a suitable shape memory metal,
for example nitinol.
[0046] The grasping element 160 of device 150 is similar in construction to the grasping
element 120 of device 110. As can be seen in FIG. 3, the device 150 is free of any
atrial stabilizing section.
[0047] As would be understood by persons of ordinary skill in the art from the above descriptions,
alternative embodiments of the device 150 may be formed, using the variations described
above with respect to the device 110. Thus, for example, the ventricular winding 152
and the grasping element 160 may comprise other forms, shapes, sizes and/or materials
as described above with respect to the device 110. The ends of the device may be rounded,
squared-off, or pointed. The device 150 may have one or more anti-rotation elements,
as described further below. The ventricular winding 152 and/or the grasping element
160 may have one or more grooves and/or holes, as described above. The device may
comprise a coating, as described above.
[0048] FIG. 4 shows another embodiment of a heart valve repair device 170. The device 170
comprises a ventricular winding 172 and a grasping element 180. The ventricular winding
172 has a generally spiral shape, defined by the wire structure of the ventricular
winding 172 forming a winding around a center 174 of the ventricular winding 172.
The wire structure of the winding emanates from the center 174 and gradually moves
away from the center 174 as it winds around the center 174. In the case of device
170, the winding of the ventricular winding 172 moves outward from the center 174
at an uneven rate. Thus, the gap between adjacent turns of the winding is non-constant,
as can be seen by a comparison between smaller inner gap 172A and larger outer gap
172B. As shown in FIG. 4, the ventricular winding 172 terminates at its outer periphery
at an atraumatic end portion 184.
[0049] In the device 170, like the device 110, the winding structure of the ventricular
winding 172 forms a path that starts from an opening at the outer periphery of the
spiral and that moves toward the center 174 of the spiral as the path winds around
the center 174 of the spiral.
[0050] The device 170, like the device 110, may be comprised of a wire having a circular
cross-section. The wire of device 170 may be formed of a suitable shape memory metal,
for example nitinol.
[0051] The grasping element 180 of device 170 may be similar in construction to the grasping
element 120 of device 110 or may be generally in the same plane as the ventricular
winding 172. As can be seen in FIG. 4, the device 170 is free of any atrial stabilizing
section.
[0052] As would be understood by persons of ordinary skill in the art from the above descriptions,
alternative embodiments of the device 170 may be formed, using the variations described
above with respect to the device 110. Thus, for example, the ventricular winding 172
and the grasping element 180 may comprise other forms, shapes, sizes and/or materials
as described above with respect to the device 110. The ends of the device may be rounded,
squared-off, or pointed. The device 170 may have one or more anti-rotation elements,
as described further below. The ventricular winding 172 and/or the grasping element
180 may have one or more grooves and/or holes, as described above. The device may
comprise a coating, as described above.
[0053] As mentioned above, the implantable heart valve repair devices 130, 150, and 170,
like the heart valve repair device 110 and other heart valve repair devices described
herein, are free of any atrial stabilizing section. Each of the implantable heart
valve repair devices 110, 130, 150, and 170 has a stabilizing section that consists
only of a ventricular stabilizing section in the form of a ventricular winding 112,
132, 152, and 172, which is adapted to engage tissue only on the ventricular side
of the valve and to stabilize the device by the interaction between the ventricular
winding 112, 132, 152, and 172 and the chords on the ventricular side of the valve.
In some embodiments, these heart valve repair devices also may be described as not
having any part that, after implantation, contacts tissue in the atrium or on the
atrial side of the valve and/or not having any part that, after implantation, extends
into the atrium or on the atrial side of the valve. However, as described above, it
is possible in some embodiments for the grasping element to extend through the valve
to the atrial side, and it may contact the leaflets. However, these embodiments may
be constructed such that neither the grasping element nor any other part of the device
is adapted to engage tissue on the atrial side of the valve in a manner that stabilizes
or anchors the device with respect to the atrium.
[0054] FIGS. 5A-5C illustrate examples of anti-rotation elements that may be used with a
heart valve repair device, including any of the heart valve repair devices described
herein. FIG. 5A shows a heart valve repair device 190 having an anti-rotation element
191 in the form of a protrusion on the end of the ventricular winding. FIG. 5B shows
a heart valve repair device 192 having an anti-rotation element 193 in the form of
an enlarged tooth on the end of the ventricular winding. FIG. 5C shows a heart valve
repair device 194 having an anti-rotation element 195 in the form of an enlarged area
on an inner turn of the winding, coming close to or touching an adjacent turn. The
anti-rotation elements can help prevent backward rotation of the device after implantation,
by allowing easier rotation of the device in the direction of bringing the chords
together than in the opposite direction. Thus, for example, a tooth having a slanted
front face (on the side facing the outer opening of the path of the spiral) and steep
back face can permit rotation of the device in the direction that brings the leaflets
together (by the chords passing over the slanted front face) and can help resist rotation
in the opposite direction (by the chords acting against steep back face, thereby resisting
backward rotation).
[0055] In the example of one or more protrusions 191 as shown in FIG. 5A, the force applied
by the delivery system during the process of turning the device 190 to capture the
chords can result in the wire structure flexing sufficiently to create a large enough
gap between the protrusion 191 and the adjacent turn of the winding in order to allow
the chords to pass therethrough, so that the device 190 may be wound around the chords.
Similarly, in the example of one or more protrusions 193 as shown in FIG. 5B, the
force applied by the delivery system during the process of turning the device 192
to capture the chords can result in the wire structure flexing sufficiently to create
a large enough gap between the tooth 193 and the adjacent turn of the winding in order
to allow the chords to pass therethrough, so that the device 192 may be wound around
the chords. Similarly, in the example of one or more enlarged areas 195 as shown in
FIG. 5C, the force applied by the delivery system during the process of turning the
device 194 to capture the chords can result in the wire structure flexing sufficiently
to create a large enough gap between the enlarged area 195 and the adjacent turn of
the winding in order to allow the chords to pass therethrough, so that the device
194 may be wound around the chords. In each of these examples, the geometry of the
anti-rotation element(s) helps prevent the device from unintentionally rotating in
the opposite direction.
[0056] FIG. 6 illustrates a proximal end of a delivery system of a type that may be used
for implanting a heart valve repair device, such as any of the heart valve repair
devices described herein. The delivery system 300 includes a flexible applicator 400,
which is generally tubular in shape, and an internal rod 450, which is moveable within
the applicator 400. An applicator gripper 310 may be used to help push, withdraw,
and rotate the applicator 400, in both clockwise and counterclockwise directions.
An applicator irrigation port 320 allows injecting irrigation fluids into the applicator
400. An internal rod torquer 330 may be used to rotate the internal rod 450 within
the applicator 400. An internal rod grip 340 is connected to the internal rod 450
and may be used to control movements of the internal rod 450, including pushing it
forward in order to eject a hook that is connected to internal rod 450, as described
below. A scale or ruler 350 facilitates measuring how far the internal rod 450 has
been advanced, so as to determine the position of the hook inside the applicator 400.
A safety plate 360 prevents inadvertent advancement of the internal rod grip 340,
in order to eliminate the possibility of accidentally pushing the hook outside of
the applicator 400.
[0057] FIGS. 7A and 7B show top and side views, respectively, of a distal end of the delivery
system 300, with a heart valve repair device 110 loaded on the delivery system 300.
In these figures, it can be seen that the flexible applicator 400 has lateral slots
402 to facilitate bending. Other manners of imparting flexibility to a catheter may
be used, including selection of appropriate flexible material(s). The applicator 400
has a rounded, atraumatic distal end 404. The applicator 400 has a window 410 through
which all or part of the heart valve repair device may be ejected. A ramp surface
420 adjacent the distal end of the window 410 facilitates ejection of the device,
as described below.
[0058] The internal rod 450 terminates in a hook 460. The hook 460 is designed to hold the
grasping element of the heart valve repair device while the hook 460 is inside the
applicator 400, proximal to the window 410.
[0059] In a first example implantation, the delivery system 300 holds a heart valve repair
device 110 as shown in FIGS. 7A and 7B, with the ventricular winding 112 positioned
outside of the lumen of the applicator 400 and with the grasping element 120 positioned
inside the lumen of the applicator 400 and held by the hook 460. In this position,
the internal wall of the lumen of the applicator 400 prevents the grasping element
120 from exiting the hook 460. Thus, as long as the hook 460 is inside the lumen of
the applicator 400 (and not in the window 410), the grasping element 120 remains hooked
on the internal rod 450 and is thereby locked to the internal rod 450.
[0060] The delivery system 300 is used in conjunction with a catheter tube, for example
a steerable catheter as is known in the art. One example of a steerable catheter is
the AGILIS catheter of St. Jude Medical, Inc. The catheter is sized to accommodate
the applicator 400 of the delivery system 300. For example, if the applicator 400
has a size of 7.5 French, the outer catheter may have a size of 12 French. This is
just an example, as other sizes may be used.
[0061] In this first example, with the ventricular winding 112 positioned outside of the
lumen of the applicator 400, the distal end of the applicator 400 is advanced into
the proximal end of the steerable catheter. Because the lumen of the steerable catheter
is only slightly larger than the outer diameter of the applicator 400, and smaller
than the outer periphery of the ventricular winding 112, as the applicator 400 is
further advanced into the catheter, an internal turn of the ventricular winding 112
comes into contact with the edge of the catheter tube at its proximal end. Further
advancement of the applicator 400 into the catheter will thereby cause the ventricular
winding 112 to unwind and straighten as it is advanced into the catheter along with
the applicator 400. It will be appreciated that the center part of the ventricular
winding 112 will be advanced into the catheter first, and the ventricular winding
112 will unwind from the center to the outer periphery as the ventricular winding
112 is advanced into the catheter. When fully advanced into the catheter, the generally
unwound ventricular winding 112 is held in a relatively straightened position between
the outer wall of the applicator 400 and the inner wall of the catheter lumen. The
applicator 400 may be advanced into the catheter either before or after the catheter
is tracked to the patient's heart.
[0062] The catheter is positioned adjacent the heart valve to be treated, for example a
mitral valve, by a method known in the art. The approach may be, for example, a transseptal
approach, with the catheter entering the left atrium through the septum between the
right atrium and the left atrium. To facilitate a transseptal approach, the delivery
system may include an atrial septum dilator. Other approaches alternatively may be
used, including, for example, a transfemoral approach through the femoral artery and
through the aorta and into the left ventricle, a transapical approach through the
heart wall at the heart apex into the left ventricle, or a transatrial approach through
the heart wall into the left atrium. Similarly, when the valve to be treated is the
tricuspid valve, the catheter is positioned adjacent the valve by a method known in
the art (such as being introduced to the heart via a jugular vein or the vena cava).
[0063] Once the guide catheter is adjacent the heart valve, the tip of the guide catheter
may be moved and/or turned so that it is facing the heart valve leaflets. The applicator
400 then may be advanced relative to the catheter, thereby ejecting the ventricular
winding 112 from the catheter. Because of the shape memory of the ventricular winding
112, the heart valve repair device 110 returns to a position as shown in FIGS. 7A
and 7B, inside the heart. The ejection of the ventricular winding 112 from the catheter
may be performed in the atrium. Alternatively, the ejection of the ventricular winding
112 from the catheter may be performed in the ventricle. If ejected in the atrium,
the delivery system 300 then may be used to advance the distal end of the applicator
400, and with it the ventricular winding 112, into the ventricle. The distal end of
the applicator 400 and the ventricular winding 112 may be pushed through the valve
into the ventricle.
[0064] FIG. 8 shows a perspective view of the distal end of the delivery system 300, with
the ventricular winding 112 ejected from the guide catheter and outside of the tube
of the applicator 400, and with the grasping element 120 still inside the tube of
the applicator 400 and connected to the hook 460. In this position, rotation of the
applicator 400 causes the heart valve repair device 110 to be rotated along with it.
During rotation of the applicator 400, the action of the frame of the window 410 against
the device 110 causes the device 110 to rotate with the applicator 400. Additionally
or alternatively, the hook 460 or another part of the delivery system 300 may sufficiently
hold the device 110 to cause the device 110 to rotate. Due to the geometry of the
device, the axis of the delivery system can be generally aligned with the axis of
rotation of the ventricular winding.
[0065] In the condition as shown in FIG. 8, and with the ventricular winding 112 positioned
in the ventricle, the delivery system may be used to capture the desired chords with
the ventricular winding 112. The physician may maneuver the ventricular winding 112
from side to side to capture specific chords in order to bring desired areas of the
leaflets together. For example, by suitably moving and turning the ventricular winding
112, the chords associated with the leaflet areas A1 and P1 (FIG. 12) may be captured.
Additionally or alternatively, the chords associated with the leaflet areas A2 and
P2 and/or A3 and P3 (FIG. 12) may be captured.
[0066] In this manner, the desired chords associated with the anterior papillary muscle
and the desired chords associated with the posterior papillary muscle are positioned
within the path 118 of the generally spiral shape of the ventricular winding 112.
By turning the ventricular winding 112, whether by turning the applicator 400 or by
another suitable mechanism, the ventricular winding 112 is thereby turned to wind
around the selected anterior and posterior chords. As the ventricular winding 112
is turned, the spiral shape forces the chords within the path 118 closer to the center
114 of the ventricular winding 112. In this manner, the captured anterior chords and
posterior chords are forced closer together, thereby reducing a gap between the selected
chords associated with the anterior papillary muscle and the selected chords associated
with the posterior papillary muscle. By doing this, because the selected chords are
attached to the selected areas of the leaflets, the selected areas of the leaflets
are brought closer together.
[0067] In order that the ventricular winding may be turned to move the chords in this manner
and may hold the chords, the heart valve repair device, or at least the ventricular
winding, should have sufficient stiffness such that the spiral shape is generally
maintained. Thus, the device should be sufficiently rigid so as to maintain the spiral
shape on its own and under the forces applied to it by the chords.
[0068] In alternative embodiments in which the ventricular winding comprises more than one
spiral, the device may be formed so that it can gather and move the chords with fewer
rotations. Thus, for example, with the ventricular winding comprising multiple spirals
and with the openings for the spirals positioned at different places around the perimeter
of the ventricular winding, chords at different places around the perimeter of the
ventricular winding may be gathered simultaneously and moved toward the center simultaneously.
[0069] In order to adjust the device, after the physician has turned the ventricular winding
112 in a first direction as described above, the physician may turn the ventricular
winding 112 back in the opposite direction in order to allow the chords to move apart
by some amount. Thus, in this example, after the positioning resulting from clockwise
turning, the physician may turn the ventricular winding 112 counterclockwise (when
viewed from the top) in order to allow the captured chords to move away from the center
114 of the ventricular winding 112, thereby allowing them to separate by some distance.
The physician can monitor the positioning of the chords and leaflets and turn the
ventricular winding 112 clockwise or counterclockwise as needed in order to obtain
the desired result.
[0070] If desired, after the ventricular winding 112 has been rotated into the desired rotational
position, the physician may pull the ventricular winding 112 to bring it closer to
the heart valve. This may be accomplished by retracting the applicator 400.
[0071] When the ventricular winding 112 is in the desired position, the remainder of the
device 110 is ejected from the applicator 400, as shown in FIG. 9. With the applicator
400 held relatively stable, the internal rod 450 is advanced distally within the applicator
400. This moves the hook 460 to be located at the window 410. During this distal advancement,
the grasping element 120 is advanced distally against the ramp surface 420, which
forces the grasping element 120 away from the applicator 400 and the hook 460. With
the hook 460 in the window 410, the grasping element 120 is no longer prevented from
exiting the hook 460 by the internal wall of the lumen of the applicator 400. The
grasping element 120 is released from the hook 460, and the device 110 is left in
place. The delivery device 300 is then withdrawn from the patient. This leaves the
heart valve repair device 110 implanted in the patient.
[0072] If the procedure is one in which the valve is approached from the atrium as described
above, once the device is implanted in the ventricle, the grasping element will be
pointing generally toward the atrium. If, on the other hand, the procedure is one
in which the valve is approached from the ventricle, once the device is implanted
in the ventricle, the grasping element will be pointing generally away from the atrium
and generally toward the apex of the heart.
[0073] Other heart valve repair devices as described herein, such as the heart valve repair
devices 130, 150, 170, and 190, and the variations described above with respect to
the heart valve repair devices 110, 130, 150, 170, and 190, may be implanted in a
similar manner as described above.
[0074] The inventive heart valve repair devices as described herein provide certain advantages
with respect to prior devices. As discussed above, in prior heart valve repair devices
for capturing leaflet chords as exemplified in certain prior devices, the devices
have included parts or sections for anchoring the devices relative to the atrium,
in order to ensure that the devices remained stable in the heart after implantation.
By contrast, the inventive heart valve repair devices 110, 130, 150, 170, and 190,
and the variations described above with respect to these devices, depart from these
prior teachings and are free of any atrial stabilizing section. The inventors have
found that not only is it possible to implant the inventive heart valve repair devices
and have them remain stable in the heart after implantation despite the absence of
any atrial stabilizing section, but the inventors also have found that the inventive
heart valve repair devices provide previously unrecognized advantages that could not
be attained by prior devices that were anchored to the atrium.
[0075] As the heart pumps, the various parts of the heart are in motion. The chords connecting
the papillary muscles to the leaflets are in motion. A heart valve repair device as
described herein without any atrial stabilizing section is free to move along with
the chords, while at the same time retaining the chords in their drawn-in condition
for leaflet coaptation. Over time, tissue may grow around the ventricular winding
such that the ventricular winding becomes substantially embedded in the chords. This
tissue enveloping of the device results in a fixation of the device to the chords.
[0076] In prior devices that have included atrial stabilizing sections, the devices have
been anchored relative to the atrium. However, during the beating of the heart and
the opening and closing of the valves, the chords move relative to the atrium. Thus,
when such a prior device is implanted and anchored to the atrium, the chord movement
relative to the atrium results in chord movement relative to the device. A device
anchored to the atrium is constrained from moving freely with the chords. This constraint
can occur at the time of the implantation procedure and longer. When a device is constrained
in this manner, the chords can rub relative to such a device, which can cause irritation,
injury, and/or rupture of the chords.
[0077] By contrast, a heart valve repair device as described herein, without any atrial
stabilizing section, can be affixed only to the chords. Thus, the device is free to
move along with the chords, such as in an up-and-down direction generally in the direction
of the axis of implantation, while at the same time maintaining the chords in their
drawn-in condition for leaflet coaptation. This movement of the device can occur relative
to the atrium. Thus, by being free of any atrial stabilizing section, the device has
the previously unrealized advantages of reducing or eliminating the potential for
chord movement relative to the device and reducing or eliminating the consequent potential
for irritation, injury, and/or rupture of the chords that can be caused by such relative
movement.
[0078] While prior devices as discussed above have included atrial anchoring in order to
ensure stability after implantation, the inventors have found that a device as described
herein, in both
ex vivo testing and
in vivo animal testing, is stable in the heart after implantation, despite not having an
atrial stabilizing section. The device is sufficiently held in place by the interaction
between the ventricular winding and the chords. Accordingly, the inventors have found
that it is possible to realize the advantages as described herein and have the device
be stable in the heart after implantation, without the need for a connected atrial
stabilizing section as in the prior devices discussed above.
[0079] The use of a device without any atrial stabilizing section can have several additional
advantages. For example, by not having an atrial stabilizing section, the device can
be smaller, simpler and less expensive to manufacture, easier to implant, more maneuverable
to facilitate targeted treatment, less prone to tissue injury, and may improve overall
outcome.
[0080] The presence of an atrial stabilizing section can result in a relatively larger or
longer device, requiring positioning the device on the atrial side as well as on the
ventricular side of the valve. Thus, the device without any atrial stabilizing section
can lead to easier implantation. Implantation is also facilitated because the device
is easier to visualize without any atrial stabilizing section.
[0081] Without an atrial stabilizing section, it can be easier to maneuver the relatively
small ventricular winding to capture specific groups of chords. The presence of an
atrial stabilizing section can limit the range of placement of the device. That is,
a relatively large atrial stabilizing section can limit the side-to-side range of
the device, potentially limiting the areas in which the device can be placed, and
limiting the groups of chords that can be captured. By contrast, the smaller, more
maneuverable device leads to an improved ability to address specific chords and/or
specific areas of a valve.
[0082] The device without an atrial stabilizing section also reduces the chance of tissue
injury on the atrial side of the valve, which can occur due to the engagement of tissue
on the atrial side. Such engagement can occur during the delivery procedure or after
implantation.
[0083] A person of ordinary skill in the art will understand that the various heart valve
repair devices described herein may be implanted according to the method described
above. Various features of the device can facilitate the procedure and functioning.
[0084] For example, the grasping element allows the device to be held by the delivery system,
so that it can be held, maneuvered, turned, and released as described above. Because
the grasping element can extend from at or near the center of the ventricular winding,
the device can be turned by simply rotating the ventricular winding generally around
the axis of the grasping element. When the device is fully deployed, the grasping
element may be located fully within the ventricle or may extend into the atrium.
[0085] The end portion of the ventricular winding, bent away from the general plane of the
winding, can facilitate capturing of the chords. The distance of the end portion away
from the general plane of the winding can determine the span of the potential chords
to be grasped. The rounded atraumatic tip of the end portion can help prevent injury
to the chords, leaflets, and/or other tissue.
[0086] When all or part of the ventricular winding is out of plane, such as in a conical
or partially-conical embodiment as shown in FIGS. 2 and 3, the height dimension of
the ventricular winding can help maintain the vertical positioning of the device within
the ventricle. The height dimension also allows more contact with the chords in the
vertical direction. This can reduce the friction between the device and the chords
and can increase tissue coverage of the device. In addition, the height dimension
can allow easier visualization of the device.
[0087] When the spacing of the turns of the ventricular winding is larger toward the outer
periphery, as shown in FIG. 4, the design can facilitate capturing the chords (by
the larger outer spacing) while also bringing them close together (by the narrower
inner spacing).
[0088] The device can have anti-rotation elements that can help prevent the ventricular
winding from turning backward (in the loosening direction) after implantation. Thus,
the ventricular winding can have one or more anti-rotation elements 191, 193, 195,
as shown in FIGS. 5A-5C, that help keep the device in place. Other mechanisms for
resisting unwinding include the use of different shapes. For example, if the ventricular
spiral is in an elliptical shape, the chords will tend to gather in the apices of
the long axis of the ellipse. In order for the device to rotate, the chords would
need to be drawn closer together, which is a movement they would tend to resist. Accordingly,
such an elliptical shape can assist in preventing an unwanted rotation of the device.
[0089] It will be appreciated that in procedures in which the delivery system approaches
the heart valve from the ventricular side (e.g., in transfemoral and transapical approaches),
similar methods to those described above may be used, modified to account for the
fact that the delivery system approaches the valve from the opposite side.
[0090] The delivery system may have means for retrieving and/or moving the heart valve repair
device after it has been partially or fully deployed. For example, FIG. 10 shows a
retraction wire 500 that may be placed inside the grasping element 121 of the heart
valve repair device. The retraction wire 500 can be located inside the applicator
400, but can also remain inside the grasping element 121 after the heart valve repair
device has been ejected from the applicator 400. Pulling the retraction wire 500 can
withdraw the heart valve repair device back, so that it can be moved to a different
position or fully removed from the patient.
[0091] FIG. 11 illustrates an alternate form of a hook 470 used to engage a relatively flat
grasping element 472. As can be seen, in this embodiment the grasping element 472
is generally in the same plane as the ventricular winding. In this embodiment, the
device is released simply by turning the hook 470 relative to the grasping element
472, such that the hook 470 can be withdrawn from the grasping element 472.
[0092] While the above method has been described with respect to a device in which the ventricular
winding is positioned outside of the applicator for delivery, as in FIG. 8, variations
are possible. For example, the ventricular winding may be positioned inside of the
applicator 400, whereby it is held in a relatively straightened position. For deployment,
the device is ejected from the applicator, at which time the ventricular winding resumes
its spiral shape.
[0093] As would be understood from the above descriptions by persons of ordinary skill in
the art, alternative embodiments of the devices 110, 130, 150, 170, and/or 190 may
be implanted generally as described above. The method of implantation may be varied
as appropriate with respect to the particular embodiment used and the particular patient
being treated.
[0094] When a device as described is placed in position as described, the spiral of the
ventricular winding reduces a gap between selected chords associated with the anterior
papillary muscle and selected chords associated with the posterior papillary muscle.
In this manner, the selected areas of the leaflets of the valve are drawn closer together.
In some instances, the control of the chords also can reduce the movement of the leaflets,
in order to help prevent prolapse. The control of the chords and the drawing of the
leaflets closer together facilitate coaptation of the leaflets, such that they can
close together sufficiently to correct the regurgitation issue. The device can be
left in place as a long-term treatment.
[0095] FIG. 12 shows a top view of leaflets of a mitral valve. A device as described herein
may be used in various positions and for gathering various chords. For example, the
device may be positioned approximately in the area of A2 and P2 near the center of
the anterior and posterior leaflets. The chords on A2 and P2 are trapped and gathered
by the spiral(s) of the ventricular winding. A rotation of the spiral would eventually
bring all such chords to the same location, which is the spiral center. In this situation,
the gap between A2 and P2 could be brought to zero. Rotating the spiral a little less
would result in a narrow gap. The device alternatively may be positioned approximately
in the area of A1 and P1, in which case the chords on A1 and P1 are trapped and gathered
by the spiral(s) of the ventricular winding, reducing the distance between A1 and
P1. The device alternatively may be positioned approximately in the area of A3 and
P3, in which case the chords on A3 and P3 are trapped and gathered by the spiral(s)
of the ventricular winding, reducing the distance between A3 and P3. A device with
a large spiral positioned approximately in the area of A2 and P2 may trap and gather
chords on A2, P2, A1, P1, A3 and/or P3, and can be used to reduce the distance between
P1 and P3, for example, or A1 and A3.
[0096] With a relatively small heart valve repair device as described herein, for example
having a ventricular winding with an outside diameter of 1.0-2.0 centimeters, for
example, it is possible to capture less than substantially all of the chords and to
capture small groups of chords. Implanting such a device may involve positioning the
spiral of the ventricular winding between chords rather than around substantially
all of the chords. Also, with a relatively small heart valve repair device as described
herein, it is possible to implant multiple devices, capturing different sets of chords.
The flow through the valve can be adjusted by selectively adjusting the different
devices. For example, one device could be placed capturing the chords on A1 and P1,
a second device could be placed capturing the chords on A2 and P2, and a third device
could be placed capturing the chords on A3 and P3. The flow can be evaluated, and
if necessary, adjusted. For example, the device at A1 and P1 could be rotated to bring
the associated chords closer together, while the device at A3 and P3 could be rotated
in an opposite direction.
[0097] In some instances, it may be desired to use the device to draw the leaflets closer
and then position a clip anchored to both leaflets or stitch or suture the leaflets
together. Thus, the device in conjunction with one or more clips, stitches or sutures
can facilitate coaptation of the leaflets.
[0098] If desired, the device may be adjusted or withdrawn at a later time, either shortly
or long after the implantation. A catheter may be used to access the device. To adjust
the device, the physician may turn the spiral of the ventricular winding as described
above (e.g., by turning the device) in order to bring the chords closer together or
to allow them to separate further apart, as desired. Thus, the turning may be done
while performing the initial implantation procedure and/or as an additional later
procedure that is separate from the implantation procedure. In this manner, the regurgitation
grade can be controlled. Alternatively, if it is desired to withdraw the device altogether,
a grasping mechanism may be used to grasp the device and pull it back into the catheter,
in essentially the reverse of the procedure that was used to deliver the device.
[0099] Numerous alternatives are possible within the scope of the invention. For example,
as mentioned above, the winding of the spiral may move away from the center at a non-constant
rate. Thus, the spiral density need not be constant.
[0100] If the device is formed as a tube, a wire or stiffening element may be placed into
the tube in order to change the stiffness and/or shape of the tube or a section of
it. For example, a stiffening element may be used to maintain the device in a first
shape for delivery (e.g., relatively straight), and the stiffening element may be
withdrawn upon delivery of the device from the delivery catheter in order to allow
the device to take its implantation shape. In another example, an inner wire may be
attached to the distal end of the tube, and the inner wire may be pulled relative
to the tube to change the shape of the tube. Pulling the inner wire applies a compressive
force to the tube. The tube may be formed with pre-shaped side cuts along the tube,
such that it bends in a predetermined pattern, e.g., a spiral pattern, when such a
load is applied. A locking mechanism may be used to lock the wire in its loaded position
relative to the tube. Different depths and widths of the side cuts and the distance
between the side cuts would determine the final shape of the tube element once a load
is applied.
[0101] The device may have other elements to monitor the functioning of the device and the
heart valve. For example, the device may be equipped with a sensor attached to the
device. The sensor may be, for example, a pressure sensor, a temperature sensor, and/or
a velocity sensor. In this way, the operation of the valve and the blood flow can
be monitored. Similarly, the device itself when formed as a tube can be used as a
"pig tail" for measuring pressure during or after the implantation procedure.
[0102] In one example of the use of sensors, the use of MEMS (microelectromechanical systems)
sensors on the device may assist in the implantation procedure or during the years
after it. Such sensors may monitor temperature, oxygen saturation, pressure, blood
velocity or similar physical characteristics. During the implantation procedure, it
is possible to use an xyz (positioning) sensor on the device to assist in the accurate
location and positioning of the device by using an external system that reads the
information transmitted from the sensor.
[0103] Sensor(s) on the device or delivery system may be part of a closed-loop system that
uses the signals from the sensor(s) as feedback for automatic delivery and positioning.
By using pressure sensors in the ventricle and atrium, the pressure can be continuously
monitored as the device is automatically adjusted. The adjustments and monitoring
can be continued until target pressure readings are achieved. This automatic positioning
with the use of feedback can eliminate the need for manual monitoring and positioning
that can be complicated and less accurate.
[0104] The device may also have an energy-producing element that produces energy by the
flow of blood around the device and/or by the pressure changes using a converter (such
as piezoelectric element that is capable of converting mechanical pulse into electric
current). The energy may charge a battery that, for example, can be used to transmit
signals from one or more sensors as described above.
[0105] From the description herein, a person of ordinary skill in the art can recognize
that certain embodiments of devices and methods disclosed herein can have several
advantages. For example, the device can safely hold the chords without requiring grasping
of the leaflets. The movement of the chords toward each other can be controlled by
the structure of the device, including, for example, the number of turns of the spiral
of the ventricular winding, the radii of those turns, and their shape.
[0106] The invention is further defined by the following items:
- 1. A device for assisting the functioning of a heart valve comprising:
a ventricular winding having a generally spiral shape adapted to be positioned on
a ventricular side of the heart valve such that chords associated with the heart valve
are positioned within the path of the generally spiral shape of the ventricular winding;
wherein the device is free of any atrial stabilizing section.
- 2. A device as in item 1, wherein the ventricular winding is substantially flat.
- 3. A device as in item 1, wherein the ventricular winding is substantially conical.
- 4. A device as in item 1, wherein the generally spiral shape of the ventricular winding
is substantially circular.
- 5. A device as in item 1, wherein the generally spiral shape of the ventricular winding
is substantially elliptical.
- 6. A device as in item 1, wherein the device, including the ventricular winding, comprises
a wire, bundle of wires, strip, rod, tube, or a combination thereof.
- 7. A device as in item 1, wherein the device is comprised at least in part of a metallic
material.
- 8. A device as in item 1, wherein the device is comprised at least in part of a shape
memory metal material.
- 9. A device as in item 1, wherein the device is comprised at least in part of nitinol.
- 10. A device as in item 1, wherein the device is comprised at least in part of a plastic
material.
- 11. A device as in item 1, wherein the device is comprised at least in part of a composite
material.
- 12. A device as in item 1, wherein the device further comprises at least one anti-rotation
element.
- 13. A device as in item 1, wherein the device further comprises a grasping element.
- 14. A device as in item 1, wherein the ventricular winding has an end portion that
is angled downwardly.
- 15. A method of repairing a heart valve comprising:
delivering a heart valve repair device to the area of the heart valve, the heart valve
repair device comprising a ventricular winding having a generally spiral shape; and
positioning the ventricular winding on a ventricular side of the heart valve such
that chords associated with the heart valve are positioned within the path of the
generally spiral shape of the ventricular winding;
wherein the heart valve repair device is free of any atrial stabilizing section.
- 16. A method as in item 15, wherein the step of positioning the ventricular winding
comprises turning the ventricular winding in a first direction such that the chords
move closer to the center of the ventricular winding.
- 17. A method as in item 16, wherein the step of positioning the ventricular winding
comprises positioning the ventricular winding such that chords associated with the
anterior papillary muscle and chords associated with the posterior papillary muscle
are positioned within the path of the generally spiral shape of the ventricular winding
and wherein the turning of the ventricular winding in the first direction reduces
a gap between chords associated with the anterior papillary muscle and chords associated
with the posterior papillary muscle.
- 18. A method as in item 16, wherein the step of positioning the ventricular winding
comprises, after turning the ventricular winding in a first direction, turning the
ventricular winding in a second direction such that the chords move further from the
center of the ventricular winding, to adjust the positioning of the chords in the
device.
- 19. A method as in item 15, wherein the step of delivering the heart valve repair
device to the area of the heart valve comprises using a delivery system, and the step
of positioning the ventricular winding comprises using the delivery system to turn
the ventricular winding in a first direction such that the chords move closer to the
center of the ventricular winding.
- 20. A delivery system for implanting a heart valve repair device for repairing a heart
valve comprising:
an applicator tube; and
an internal rod within the applicator tube;
wherein the internal rod is adapted to hold the heart valve repair device during maneuvering
of the device; and
wherein the delivery system is adapted to release the heart valve repair device by
advancement of the internal rod relative to the applicator tube after positioning
the heart valve repair device in the desired location.